So here are 11 cards with basically the same design, yet you can see that nothing is exactly alike.
Honestly, the only one where I have any serious critique on the forest part is the top center one above, where the trees are a bit scattered and go much further up on the card. But even that one looks fine. The others all look great, I think (both above and below). You can tell the ones I did together - I just stamped all the way across the bottom of the cardstock and then cut it in two afterwards. You can kind of see my progress as I did more of the tree stamping - I'm not sure if the one at the bottom right below is actually the last one I did, but it seems the most "realistic"-looking in terms of the way the trees fade into the background.
I also experimented around with various borders on the "jingle" ones below. I do like the one with the white border all the way around but again, I think they all look fine, with and without.
Ellen Hutson stamp set that had that stamp, but instead I went looking for a "jingle bell" stamp - that is, one with a picture of a bell. I wanted one I could put it on the inside of the card, so at least there was a follow-through with the saying. (Some people that get the card may not even notice, but at least *I* am happy, that way.) I ended up getting this one from Paper Source, and I stamped it on the inside in Real Red and it looks cute.
(And then, naturally, I ended up buying two boxes of cards and a calendar from Paper Source while I was at it. That place is dangerous.)